The mount combo would be ideal for my workspace but I have a 34 inch ultra-wide Asus Rog Swift PG348Q screen and a 17 inch laptop as well, and I was wondering if there would be enough room with those two combined? Or would it be too tight of a fit?

I plan on installing the mount in the Pilot House of a boat. The windows of the Pilot House slope inward so in order to clear the windows I need to know the height of the mount. In addition does the top of an iMac 27 or a Thunderbolt display extend above the top of the mount and if so by how much?

As you correctly stated, this mount cannot be used in conjunction with the aluminum stand that is built into the iMac. While the stand was removable in older models, it is not in newer models (Late 2012 or later).

To use this mount with a newer iMac, you need to configure a special wall-mountable model at the time of purchase. These models don't come with a stand, but include a built-in VESA mount adapter instead.

Bretford told me it is 31 lbs per arm, not total. They also told me it is not "officially approved" for two monitors. That said, I just installed it with one 30" and one 24" Apple displays and it works just fine, I would not hesitate to put two 30" displays on it. It is extremely over engineered (built like a tank)- I suspect it will hold several times the stated weight (but I wouldn't recommend going past the 31 lbs per arm). By the way - it comes with 2 VESA brackets - the stand for the laptop just bolts onto one of the VESA mounts - so you only need the Apple VESA adaptors and you are ready to go!!

By default you have to drill holes to fit it to the desk, but I spoke to the manufacturer and there is a clamp fitting available so that it can attach to the edge of a desk without the need for drilling holes.

I just looked at the assembly guide on Bretford's website, apple.bretford.com, and it appears that the two arms are identical and interchangeable. The plate for the laptop attaches just like a VESA mount, and the interface at the end of each arm look the same so it appears you could set up the screen/iMac on the right with the laptop on the left. You just have to assemble it that way.